This invention relates to improvements in domed building structures.
The prior art has provided numerous forms of roof structures. Passive self-supporting structures include the cast-in-place shell structures of Luigi Nervi, which structures require extensive and complex forms and staging thus giving rise to substantial construction costs. Other passive structures include the elegant but complex lattice-work geodesic domes and cupolas as designed by Buckminister Fuller, the well known American designer. Other domed structures have been formed of wood, sheet metal, fibre glass and the like. Most of these structures require additional frame supports or panel stiffeners and/or special means for attaching the panels together thus giving rise to high installation costs.
Active roof supports include flexible air pressure supported domes made from air impervious fabrics or from thin sheets of stainless steel. Such structures have and are being used in large buildings such as sports stadiums, hockey rinks and the like. The disadvantages include high installation/operating costs due to the need for energy consuming blower systems to maintain air pressure, air lock doors etc. as well as the ever present danger of structural collapse in the event the thin roof material is pierced or torn by a moving object and/or the blower systems or air locks fail. A collapse of this nature, especially when the roof is carrying a substantial snow load, can produce disasterous results.